<!DOCTYPE html>
<html>
  <head>
    <title>menclose unknown</title>
    <meta charset="utf-8"/>
  </head>

  <body>
    <math>
      <menclose notation="circle">
        <mspace width="100px" height="50px" mathbackground="blue"></mspace>
      </menclose>
    </math>
  </body>
</html>
